Sagot :
[tex] -10x^2-41x-21=\\
-10x^2-35x-6x-21=\\
-5x(2x+7)-3(2x+7)=\\
-(5x+3)(2x+7)[/tex]
[tex]-10x^2-41x-21= -(10x^2+41x+21) =-(10x^2+35x+6x+21)=\\\\=- [(10x^2+35x)+(6x+21 )]=- [5x(2x +7 )+3(2x+7 )]=-(2x+7)(5x+3)[/tex]